X-ray – treatment, effect & risks

At the end of the 19th century, Wilhelm Conrad Röntgen discovered X-rays almost “accidentally” – as with many great inventions. This radiation is able to penetrate through tissue and blacken underlying films. Depending on the density of the penetrated tissue, the film behind it is more or less blackened – so bones in particular can be displayed extremely well. Only after years of experimenting with X-rays did he realize that radiation also has negative effects: it damages the skin and can cause tumors.

Principle and mode of action

The principle of X-rays is relatively simple: a filament as in a conventional light bulb is heated so much that electrons detach from the material and “buzz” around the wire.Subsequently, a strong voltage is applied (between 50,000 and 150,000 volts) so that the electrodes are pulled from the cathode (the glow wire) to the anode (the opposite pole).

If the electrons finally hit the anode at their very high speed due to the high voltage, they are not simply swallowed there, but only deflected.

Due to the deflection, they lose energy, which leaves the anode as electromagnetic radiation of very short wavelength – X-rays.

Through further technical details, this X-ray radiation can now be controlled in such a way that it only leaves the X-ray tube in one direction and the patient is only exposed to this radiation in a clearly defined field.

Function and application

Röntgen makes sense in the classic question of “fracture suspicion”. However, X-rays of the lungs and abdomen (abdomen) are very often taken, as many diagnoses can be made on the basis of a simple X-ray: free air during intestinal perforation, mirroring in ileus (intestinal obstruction), pleural effusion or pneumothorax (fluid or air between the leaves of the pleura) are just a few of them.

Important in the application of X-rays is always the correct indication. Although a general practitioner can request an X-ray examination, a radiologist always decides whether the examination really makes sense for the patient and the question. It is also always important that pregnancy is excluded in women, as unborn children react very sensitively to radiation and can trigger malformations even a small dose. With the help of a rotating X-ray tube (computer tomograph), cross-sectional images can be made that offer much more information than conventional X-ray images.

In addition, so-called contrast agents can be used in computed tomography, which further increase image quality. However, a computed tomography means a higher radiation exposure for the patient, so that it must be carefully weighed whether a single X-ray image may be sufficient. Useful indications for computed tomography are, for example, the suspicion of a pulmonary embolism or bleeding in the brain or abdomen.

What needs to be considered in advance?

An X-ray examination always proceeds in the same way. First, the attending physician issues an X-ray certificate on which he notes the patient’s illness, the desired examination and the question. With this certificate, the patient goes to the X-ray department of a hospital or to an X-ray practice. There, a radiologist checks whether the examination is justified in this patient. If so, an X-ray assistant takes over the patient and performs the X-ray examination.

To do this, the patient must remove all metal that can be removed from the area examined. Piercings and earrings must be removed, jeans must be taken off, pacemakers are left naturally in the body. Subsequently, the patient is positioned for examination. During the recordings, breathing commands are sometimes given, the patient is not allowed to move. The examination itself takes a maximum of a few minutes. Subsequently, the images are evaluated, the radiologist makes a report and sends it to the attending physician. This then decides together with the patient on the further procedure.

Risks, side effects and dangers

There are no side effects from X-rays. The risks are limited. Any application of radiation can induce tumors , but this risk must always be weighed against the information obtained from the examination. With CT , the radiation exposure is much higher, so it should be considered more carefully whether the examination makes sense.

If contrast agents are used in computed tomography, side effects may occur.In the case of hyperthyroidism, a so-called thyrotoxic shock can occur and in the case of poor kidney function, the kidneys can be damaged up to renal insufficiency.

However, the risk of these two side effects is minimized by testing thyroid and kidney levels in the laboratory before using contrast agent.

In addition, contrast agent administration can lead to contrast agent allergies, which can lead to death. However, this is extremely rare and, if detected in time and treated correctly, can be well prevented or stopped.